The vegetation is rainforests grows in distinct layers (see the diagram below), and has adapted to the climate and poor soils Adaptations to climate:
The tropical rainforest's bidiversity is a response to climate. There are constant high temperatures, with a mean monthly average above 27 degrees Celsuis, accompanied by high solar light intensity. Rainfall is regular and high, with above 2000mm falling during the year, which creates humid conditions.
Plant communities are fiercely competitive. There is survival of the tallest as the tall trees are drawn upwards by the heat and light, which is why leaf growth is concentrated in the canopy. The leathery upper surfaces of the trees' leaves are necessary to withstand the great power of the sun's rays. The drip tips help the leaves to shed water during the heavy rains.
In the lower layers of the forest, sunlight is in short supply. Ferns are adapted to life on the forest floor by having leaves which intercept a high proportion of the light that reaches there. The shrub layer is sparse because a lack of light, although shrubs quickly take advantage of any gap in the forest canopy.
More plant adaptations:
trees are branchless and the trunks are tall and thin - this helps them to reach the light from the sun more easily
trees are evergreen - this helps them take advantage of the continuous growing season. The can shed their leaves at any time of year
leaves often have drip tips - this helps them to shed the heavy rain, and also helps protect them from hungry insects
some trees have large buttress roots - these support them in the shallow soil. Others spread their roots over the surface - this helps them capture as many of the available nutrients as possible
lianas are woody climbing vines which drape the rainforest. They climb high into the canopy to reach the sunlight, dropping their roots down to the ground
epiphytes are plants that grow in the branches of trees - they use the tree for support, not for food
The Atlantic Forest
The golden-headed lion tamarin lives in one place and one place only - the Atlantic Forest of South America. it lives nowhere else on Earth. Not only that it is an endangered species as the rainforest is being rapidly cut down. Many species here are endemic which are species which can only be found in one place. The rainforest is under threat for a number of reasons and probably began as far back as the 16th century.
Why is deforestation happening in the Atlantic forest and the Amazon Rainforest?
Population pressure - caused by rapid population growth in coastal cities like Rio de Janeiro and Sao Paulo - as the towns get bigger more of the rainforest is being cut down
Debt repayments - in the late 1980s, Brazil's government had to repay large loans taken out between 1965 and 1985. Brazil's farmers were put undeer pressure to produce more and earn more to help repay the debt, this meant more rainforest had to be cut down
Large-scale farming - intially to grow cash crops like coffee, tobacco and eucalyptus. ocne the soil's fertility drops, the farmland is often converted into huge cattle ranches
Mining - The Carajas mine in Brazil is huge - its the world's biggest iron ore mine, In Carajas manganese,copper, tin, aluminium and gold are also mined. Often the land is left ruined and many pollutants wash into rivers. Cobalt and Copper are the main minerals in mobile sim cards
Road building - big projects like mines need new roads to reach them, and to transport the mined ore to processing plants and the coast for export. Roads can also be used for basic communications and to carry wood and farming goods
Slash and burn - this is the traditional method of farming used by Amerindians in the Amazon Rainforest. A small area of land is cleared and farmed for a few years, before the people leave it and move on.
Logging - (cutting down of trees) for expensive timber, such as mahogany for furniture, and for basic wood yo make timber products like pulp and paper
Small farms - an increase in the number of small farms. Landless people move out the cities or migrate from the countryside in Brazil or from countires like Paraguay and Argentina and set up new farms and homes here - so more trees are cut down
Expansion of heavy industry - as a result of Brazil's development a lot of land has been cleared for industry
What are the impacts of deforestation on Atlantic Forest and the Amazon Rainforest?
the area's Amerindians have watched their land and way of life disappear before their eyes - when they meet new people they often get diseases and unfortunately die as they no immunity
with no rainforest vegetation to protect the soil, heavy rainfall washes it away. The farmers will then need to clear more land
when rainfores is cleared and the land is intensivlely farmed, it loses its fertility within 20 years)
deforestation breaks the nutrient cycle, which the soil depends on for its fertility (see the diagrams below)
the loss of so much forest has helped to contribute to global warming. The rainforest absorbs carbon dioxide from the atmosphere. But clearing the trees and burning them just adds to the problems
Tropical rainforests: the natural vegetation found in the tropics, well suited to the high temperatures and heavy rainfall associated with these latitudes
Leaching: the dissolving and removal of nutrients from the soil, typically very effective in tropical rainforests on account of the heavy rainfall
Primary (virgin) rainforest: rainforest that represents the natural vegetation in the region unaffected by the action of people
Deforestation: the cutting down and removal of forest
Clear felling: absolute clearance of all trees from an area
Selective logging: the cutting down of selected trees, leaving most of the trees intact
Slash and burn: a form of subsistence farming practised in tropical rainforests involving selective felling of trees and clearance of land by burning to enable food crops to be planted
On this webpage you will find information on the following:
The climate of the tropical rainforest
Soils
A latosol - tropical rainforest soil
Nosies and sounds of the tropical rainforest -
http://www.bbc.co.uk/learningzone/clips/images-of-a-tropical-rainforest-biome/3205.html
The vegetation
The vegetation is rainforests grows in distinct layers (see the diagram below), and has adapted to the climate and poor soils
Adaptations to climate:
The tropical rainforest's bidiversity is a response to climate. There are constant high temperatures, with a mean monthly average above 27 degrees Celsuis, accompanied by high solar light intensity. Rainfall is regular and high, with above 2000mm falling during the year, which creates humid conditions.
Plant communities are fiercely competitive. There is survival of the tallest as the tall trees are drawn upwards by the heat and light, which is why leaf growth is concentrated in the canopy. The leathery upper surfaces of the trees' leaves are necessary to withstand the great power of the sun's rays. The drip tips help the leaves to shed water during the heavy rains.
In the lower layers of the forest, sunlight is in short supply. Ferns are adapted to life on the forest floor by having leaves which intercept a high proportion of the light that reaches there. The shrub layer is sparse because a lack of light, although shrubs quickly take advantage of any gap in the forest canopy.
More plant adaptations:
How is the rainforest being destroyed?
Deforestation in Malaysia -
The Atlantic Forest
The golden-headed lion tamarin lives in one place and one place only - the Atlantic Forest of South America. it lives nowhere else on Earth. Not only that it is an endangered species as the rainforest is being rapidly cut down. Many species here are endemic which are species which can only be found in one place. The rainforest is under threat for a number of reasons and probably began as far back as the 16th century.
Why is deforestation happening in the Atlantic forest and the Amazon Rainforest?
What are the impacts of deforestation on Atlantic Forest and the Amazon Rainforest?
Video on rainforest destruction -
http://www.bbc.co.uk/learningzone/clips/rainforest-destruction-kalimantan-indonesia-and-costa-rica/3096.html
Key terms:
Tropical rainforests: the natural vegetation found in the tropics, well suited to the high temperatures and heavy rainfall associated with these latitudes
Leaching: the dissolving and removal of nutrients from the soil, typically very effective in tropical rainforests on account of the heavy rainfall
Primary (virgin) rainforest: rainforest that represents the natural vegetation in the region unaffected by the action of people
Deforestation: the cutting down and removal of forest
Clear felling: absolute clearance of all trees from an area
Selective logging: the cutting down of selected trees, leaving most of the trees intact
Slash and burn: a form of subsistence farming practised in tropical rainforests involving selective felling of trees and clearance of land by burning to enable food crops to be planted